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UCC28C42: DC Open-loop Gain of the Fixed-Frequency Voltage Control Loop of A Peak Current Mode Flyback Converter

Part Number: UCC28C42

Hi,

I have read the data sheet of UCC28C42, it is useful for my design. However, I still couldn't understand equation 19. Would you mind show me the derive process of that equation or help me understand that equation?

Cuz the equation cannot be showed well in this blank, please view the datasheet by clicj here:

Thanks,

Qiusen

  • Hi,

    Let me look at this and will reply to you how this equation obtained.

  • Hi,

    Equation 19 is actually based on research work on CCM flyback peak current mode feedback loop study. The development is presented such as in the below references, and based on state averaging approach for small signal model analysis. To find out how equation 19 is obtained, you need to read through these references for example the below. It is impossible to copy and paste these research work descriptions here.

    (1) Christophe P. Basso, “Switch-Mode Power Supplies Spice Simulations and Practical Designs”, McGraw_Hill, 2008.

    (2) W. Kleebchampee and C. Bunlaksananusorn, “Modeling and Control Design of a Current-Mode Controlled Flyback Converter with Optocoupler Feedback”, IEEE PEDS 2005.

    (3) Yuri Panov and Milan M. Jovanovic´, “Small-Signal Analysis and Control Design of Isolated Power Supplies with Optocoupler Feedback”, IEEE TRANSACTIONS ON POWER ELECTRONICS, JULY 2005.

  • Hi,

    Appreciate your help.